Note 2 – Intangible Assets

Intangible assets at March 31, 2022 and December 31, 2021 consisted of the following:

 Summary of Intangible Assets

Gross intangible assets consist primarily of costs we capitalized when we acquired the license rights to PCS499 in 2018. These costs represented intangible assets to be used in research and development activities that management believes has future alternative uses.

Amortization expense was $197,124 and $198,832 for the three months ended March 31, 2022 and 2021, respectively, and is included within research and development expense in the accompanying condensed consolidated statements of operations. As of March 31, 2022, our estimated amortization expense for the year ended December 31, 2022 and for annual periods thereafter until the asset is fully amortized is approximately $788,000.